Re: Y Combinator is restoring one of Alan Kay's Xerox Alto machines

[Curious Marc]

Session 7:
https://youtu.be/c0sL_FwPVwM
We discovered we do not have a boot disk, but the LCM is shipping us one. In 
the meantime we have fun testing some specialized Alto tools we built. 
Marc

Sent from my iPhone

> On Sep 10, 2016, at 7:46 PM, CuriousMarc  wrote:
> 
> Video of session 6 is up:
> https://youtu.be/b7yVhMT7tr4
> Found our first bad IC. Probably not our last one.
>  
>  
> On 9/3/16 11:08 PM, curiousma...@gmail.com wrote:
> Episode 5, still does not boot, but we are starting to follow long why:
> https://youtu.be/Wr7vDZpniNIr
>  
> Marc
>  
>  
> On Jul 31, 2016, at 6:12 PM, CuriousMarc  wrote:
>  
> Next Episode:
> https://youtu.be/EDw8U1a6s78
> http://www.righto.com/2016/07/restoring-y-combinators-xerox-alto-day_31.html
> Marc
>  
> From: Curious Marc [mailto:curiousma...@gmail.com] 
> Sent: Tuesday, July 12, 2016 2:01 AM
> To: Curious Marc; cctalk@classiccmp.org
> Subject: Re: Y Combinator is restoring one of Alan Kay's Xerox Alto machines
>  
> Ken's in-depth blog post to go with the previous video
> http://www.righto.com/2016/07/restoring-y-combinators-xerox-alto-day_11.html
>  
> On Jul 5, 2016, at 2:46 PM, Curious Marc  wrote:
>  
> Video from yesterday’s work on the Diablo cartridge disc:
> https://youtu.be/PR5LkQugBE0
> Should be up in a few minutes.
> We were tickled pink to have official representation from PARC (former Xerox 
> Parc) at the session.
> Marc
>  
> Ken’s new post on the monitor repair to go with my previous video.
> http://www.righto.com/2016/07/restoring-y-combinators-xerox-alto-day.html
> Al Kossow got us a new CRT tube, so we are probably going to try that this 
> week-end.
> Marc
>  
>  
> Latest entry from Ken Shirriff, trying out BCPL (ancestor of C). On the 
> emulator, not yet on the real machine:
> http://www.righto.com/2016/06/hello-world-in-bcpl-language-on-xerox.html
>  
> Marc
>  
> There are only two entries right now:
> http://www.righto.com/2016/06/y-combinators-xerox-alto-restoring.html
> http://www.righto.com/2016/06/restoring-y-combinators-xerox-alto-day.html
> Marc
>  
>  
>  

Re: Meaning of "architecture width" - Re: 68K Macs with MacOS 7.5 still in production use...

[Chuck Guzis]

On 09/17/2016 01:11 PM, Paul Koning wrote:
> 
> One other example of a machine that confuses the picture is the CDC
> 6000 series peripheral processor.  I doubt there would be much
> objection to calling that a 12 bit architecture.  But its main
> register (the accumulator) is 18 bits wide.

And, in my attempt to stir up the hornet's nest, I pointed out that
there were machines with no fixed word length, nor any
programmer-visible registers--not even the P-counter.

Our modern orthodoxy has spoiled our view of the world.

--Chuck

Re: Meaning of "architecture width" - Re: 68K Macs with MacOS 7.5 still in production use...

[Camiel Vanderhoeven]

Op 17 sep. 2016 8:34 p.m. schreef "Guy Sotomayor Jr" :
>
>
> > On Sep 17, 2016, at 10:10 AM, Chuck Guzis  wrote:
> >
> > On 09/17/2016 09:23 AM, Eric Smith wrote:
> >
> >> I don't know what the width of the TMS9900 ALU is, but I'm pretty
> >> sure it's not bit-serial, as an add instruction only takes 14 clock
> >> cycles, including four memory cycles. I'd be very surprised if the
> >> ALU isn't either 8 or 16 bits, though 4 might be possible.
> >>
> >> Possibly someone is confused by the bit-serial "CRU' I/O space, but
> >> that is unrelated to the ALU width.
> >
> > Could very well be--I'm just going by other's appraisals of the
> > architecture.
> >
> > But there were some "8 bit" MPUs with bit-serial ALUs, so the question
> > is still valid.
> >
>
> Why?  What does the width of the ALU have to do with the “bitness” of the
> architecture?  If the programmer’s view is 8-bits (or 16 or 23, or ??),
> what does it matter (other than performance) what the width of the
internal
> data paths or ALU are?
>
> It’s interesting from an implementation point of view but not really
> anything else.
>
> In a previous email, I mentioned the IBM 360 as an example of a 32-bit
machine
> (architecture) that had 8, 16 and 32 bit internal data paths and I don’t
think
> anyone would suggest that the 360 models that did not have 32-bit data
paths
> wasn’t a 32-bit “machine”.

Don't forget about the 64-bit implementations, like the model 65.

>
> The same could be said for the PDP-8/s.  That’s a bit serial machine but
it
> is a member of the PDP-8 family.  Would you call it a 1-bit machine or a
12-bit
> machine?
>
> That’s why (in my previous email) I made the distinction between
architecture
> and implementation.  The reference “machine” (which I’ve intentionally
used here)
> is somewhat ambiguous and I tend to use architecture or implementation
when I
> want to be specific.
>
> TTFN - Guy
>

Re: Meaning of "architecture width" - Re: 68K Macs with MacOS 7.5 still in production use...

[Paul Koning]

> On Sep 17, 2016, at 3:03 PM, Lyle Bickley  wrote:
> 
> ...
> Since I have a running PDP-8/S as an example, I want to back up what Guy
> has said.
> 
> The User Manual for the PDP-8/S says: "The PDP-8/S is a one-address,
> fixed word length, serial computer using a word length of 12-bits plus
> parity and two's complement arithmetic."
> 
> So the architecture is 12-bits and the implementation is serial.

Perhaps the best way to look at this question is that the architecture width of 
an architecture is what the architect says it is.

It's often the width of the registers, but not always.  It may be the width of 
the memory, but not necessarily.  It may or may not match the width of the 
system bus (if there is one) or the main data paths -- but often it doesn't.

One other example of a machine that confuses the picture is the CDC 6000 series 
peripheral processor.  I doubt there would be much objection to calling that a 
12 bit architecture.  But its main register (the accumulator) is 18 bits wide.

paul

Re: Meaning of "architecture width" - Re: 68K Macs with MacOS 7.5 still in production use...

[Noel Chiappa]

> From: Guy Sotomayor Jr

> Why? What does the width of the ALU have to do with the "bitness" of
> the architecture? If the programmer's view is 8-bits .., what does it
> matter (other than performance) what the width of the internal data
> paths or ALU are?
> It's interesting from an implementation point of view but not really
> anything else.

What he said (and others made the same point).

When talking about processors, "Architecture" = 'what the programmer sees'.


> From: Fred Cisin

> There are more than a hundred different parameters involved. There is
> no definitive agreement as to which parameter is to be used for the
> classification, nor even which parameterS. ... a product that has one
> classification by one parameter, and a different classification by
> another parameter, there will be disputed classifications, since
> different parameters are more or less important to each viewer.

And this too.

(Which is why, for the 68K, I listed several of the main user-visible
parameters, and noted that they were all 32 bits.)

Noel

Re: Meaning of "architecture width" - Re: 68K Macs with MacOS 7.5 still in production use...

[Lyle Bickley]

On Sat, 17 Sep 2016 11:38:13 -0700
Guy Sotomayor Jr  wrote:

> > On Sep 17, 2016, at 10:10 AM, Chuck Guzis  wrote:
> > 
> > On 09/17/2016 09:23 AM, Eric Smith wrote:
> >   
> >> I don't know what the width of the TMS9900 ALU is, but I'm pretty
> >> sure it's not bit-serial, as an add instruction only takes 14 clock
> >> cycles, including four memory cycles. I'd be very surprised if the
> >> ALU isn't either 8 or 16 bits, though 4 might be possible.
> >> 
> >> Possibly someone is confused by the bit-serial "CRU' I/O space,
> >> but that is unrelated to the ALU width.  
> > 
> > Could very well be--I'm just going by other's appraisals of the
> > architecture.
> > 
> > But there were some "8 bit" MPUs with bit-serial ALUs, so the
> > question is still valid.
> >   
> 
> Why?  What does the width of the ALU have to do with the “bitness” of
> the architecture?  If the programmer’s view is 8-bits (or 16 or 23,
> or ??), what does it matter (other than performance) what the width
> of the internal data paths or ALU are?
> 
> It’s interesting from an implementation point of view but not really
> anything else.
> 
> In a previous email, I mentioned the IBM 360 as an example of a
> 32-bit machine (architecture) that had 8, 16 and 32 bit internal data
> paths and I don’t think anyone would suggest that the 360 models that
> did not have 32-bit data paths wasn’t a 32-bit “machine”.
> 
> The same could be said for the PDP-8/s.  That’s a bit serial machine
> but it is a member of the PDP-8 family.  Would you call it a 1-bit
> machine or a 12-bit machine?
> 
> That’s why (in my previous email) I made the distinction between
> architecture and implementation.  The reference “machine” (which I’ve
> intentionally used here) is somewhat ambiguous and I tend to use
> architecture or implementation when I want to be specific.
> 
> TTFN - Guy

Since I have a running PDP-8/S as an example, I want to back up what Guy
has said.

The User Manual for the PDP-8/S says: "The PDP-8/S is a one-address,
fixed word length, serial computer using a word length of 12-bits plus
parity and two's complement arithmetic."

So the architecture is 12-bits and the implementation is serial.

However, just to muck things up - it is really implemented both as a
serial and parallel machine! The logic is one-bit serial - and the
memory is 12-bit parallel. The serial logic runs on one clock - and the
memory on another clock. It's one of the things that makes debugging a
PDP-8/S and "interesting" experience ;)

Cheers,
Lyle
-- 
73  AF6WS
Bickley Consulting West Inc.
http://bickleywest.com

"Black holes are where God is dividing by zero"

Re: interesting ... look at both these HP desktops - style come to the comput...

[COURYHOUSE]

Christian, Thanks  for  those links1
 
Yes  the packard bell  wegge  corner computer 
I actually need one of those  for a display here
ed sharpe archivist  for smecc  _www.smecc.org_ (http://www.smecc.org)  
 
 
In a message dated 9/17/2016 8:25:46 A.M. US Mountain Standard Time,  
captainkirk...@gmail.com writes:

On 17  September 2016 at 01:38,   wrote:
> look  at both these HP desktops -  style come to thecomputer!
>
If we're going to talk about "modern" computers... I'd  like to direct
the list to these YouTube videos by Clint, of the Lazy Game  Reviews
channel (is he on this list?):

"Strangest Computer Designs  of the '90s": 
"Strangest Computer  Designs of the 2000s": 

There's  also actual classic computer stuff on his channel too. Here's
an example of  him talking about his IBM 5160  PC/XT:


Cheers,
Christian
--  
Christian M. Gauger-Cosgrove
STCKON08DS0
Contact information  available upon request.

Re: Meaning of "architecture width" - Re: 68K Macs with MacOS 7.5 still in production use...

[Guy Sotomayor Jr]

> On Sep 17, 2016, at 10:10 AM, Chuck Guzis  wrote:
> 
> On 09/17/2016 09:23 AM, Eric Smith wrote:
> 
>> I don't know what the width of the TMS9900 ALU is, but I'm pretty
>> sure it's not bit-serial, as an add instruction only takes 14 clock
>> cycles, including four memory cycles. I'd be very surprised if the
>> ALU isn't either 8 or 16 bits, though 4 might be possible.
>> 
>> Possibly someone is confused by the bit-serial "CRU' I/O space, but 
>> that is unrelated to the ALU width.
> 
> Could very well be--I'm just going by other's appraisals of the
> architecture.
> 
> But there were some "8 bit" MPUs with bit-serial ALUs, so the question
> is still valid.
> 

Why?  What does the width of the ALU have to do with the “bitness” of the
architecture?  If the programmer’s view is 8-bits (or 16 or 23, or ??), 
what does it matter (other than performance) what the width of the internal
data paths or ALU are?

It’s interesting from an implementation point of view but not really
anything else.

In a previous email, I mentioned the IBM 360 as an example of a 32-bit machine
(architecture) that had 8, 16 and 32 bit internal data paths and I don’t think
anyone would suggest that the 360 models that did not have 32-bit data paths
wasn’t a 32-bit “machine”.

The same could be said for the PDP-8/s.  That’s a bit serial machine but it
is a member of the PDP-8 family.  Would you call it a 1-bit machine or a 12-bit
machine?

That’s why (in my previous email) I made the distinction between architecture
and implementation.  The reference “machine” (which I’ve intentionally used 
here)
is somewhat ambiguous and I tend to use architecture or implementation when I
want to be specific.

TTFN - Guy

Re: Meaning of "architecture width" - Re: 68K Macs with MacOS 7.5 still in production use...

[Chuck Guzis]

On 09/17/2016 09:23 AM, Eric Smith wrote:

> I don't know what the width of the TMS9900 ALU is, but I'm pretty
> sure it's not bit-serial, as an add instruction only takes 14 clock
> cycles, including four memory cycles. I'd be very surprised if the
> ALU isn't either 8 or 16 bits, though 4 might be possible.
> 
> Possibly someone is confused by the bit-serial "CRU' I/O space, but 
> that is unrelated to the ALU width.

Could very well be--I'm just going by other's appraisals of the
architecture.

But there were some "8 bit" MPUs with bit-serial ALUs, so the question
is still valid.

--Chuck

Re: Meaning of "architecture width" - Re: 68K Macs with MacOS 7.5 still in production use...

[Eric Smith]

On Fri, Sep 16, 2016 at 5:41 PM, Chuck Guzis  wrote:
> The TMS9900 has already been identified as a 16-bit ISA, even with its
> bit-serial ALU.

I don't know what the width of the TMS9900 ALU is, but I'm pretty sure
it's not bit-serial, as an add instruction only takes 14 clock cycles,
including four memory cycles. I'd be very surprised if the ALU isn't
either 8 or 16 bits, though 4 might be possible.

Possibly someone is confused by the bit-serial "CRU' I/O space, but
that is unrelated to the ALU width.

Re: interesting ... look at both these HP desktops - style come to the computer!

[Christian Gauger-Cosgrove]

On 17 September 2016 at 01:38,   wrote:
> look at both these HP desktops -  style come to the   computer!
>
If we're going to talk about "modern" computers... I'd like to direct
the list to these YouTube videos by Clint, of the Lazy Game Reviews
channel (is he on this list?):

"Strangest Computer Designs of the '90s": 
"Strangest Computer Designs of the 2000s": 

There's also actual classic computer stuff on his channel too. Here's
an example of him talking about his IBM 5160 PC/XT:


Cheers,
Christian
-- 
Christian M. Gauger-Cosgrove
STCKON08DS0
Contact information available upon request.

Re: Anyone have any info on a Tektronix X221CHT?

[Jules Richardson]

On 09/16/2016 03:38 PM, Ethan Dicks wrote:

On Fri, Sep 16, 2016 at 4:20 PM, Steven M Jones  wrote:

On 09/15/16 22:24, Ethan Dicks wrote:

Hi, All,

I unearthed what appears to be a Tektronix X terminal, marked on the bottom:

MODEL: X221CHT


I'd guess that the human-readable model is probably XP221...


Hi, Steve,

That's a great tip!


However you might find a usable PSU
under eBay #271338697806. Ouch, $80 + S


Nah.  Just going to jam some +5V into the right pins.


Tek made some very nice X terminals, I worked with them in the '91-'94
period.


I've worked with some X terminals, just not these.


There's a Linux how-to for supporting/booting Tek X terminals that
includes the pinouts for the power connection. Good luck with the 16
year old links for software, however...

https://web-docs.gsi.de/~kraemer/COLLECTION/NCD/xp200_linux.html


That's a great document.  Very useful info in it.  Enough to test out
the hardware.  Bummer about the NCD ftp server not answering (unless
ftp is just blocked from where I am, which is possible).

Anyone have a mirror of the old NCD repo?


This might be where the necessary NCBridge stuff ended up:

http://www.thinpathsystems.com/index.php?modules=support=patches=ncb

... depending on their definition of "patch". Makes me think of overlays to 
original software (i.e. the binary equivalent of a source file patch), but 
maybe it is a complete, self-contained archive of everything that you need 
on the host side.


cheers

Jules

Re: Meaning of "architecture width" - Re: 68K Macs with MacOS 7.5 still in production use...

[Chuck Guzis]

On 09/16/2016 07:33 PM, Cameron Kaiser wrote:

>> The PB250 is serial throughout--the registers are implemented as 1
>> bit recirculating devices that are 22 bits in length.  Memory is
>> addressable in 22 bit words (no shorter unit of addressing is
>> present) and is again, loops of recirculating serial data.  Basic
>> operations are performed on 22-bit words.  FWIW, it's a
>> one-plus-one instruction set.
> 
> So why wouldn't this be a 22-bit architecture?
> 

Simply because, as you noted on the TMS9900, a data path can override
the consideration that a machine has a 1-bit ALU.

In the PB250 there are no 22-bit data paths in the whole machine.  As a
matter of fact, the PB250 has on the order of only 400 transistors (lots
of diodes, however).

So, does the internal  data path width to the machine bear on the
bit-edness of the architecture?

As I pointed out, since, on a machine with no user-visible registers,
the bit-edness can be anything if you ignore data path widths.  A
bit-serial memory and ALU could define a word size to be thousands of
bits--all that would be needed is a bit counter to keep one's position
within a "word".

In particular, there were variable word-length machines, so a machine
could have a mixture of word sizes all in play at the same time.  But if
you define a machine by the minimum width of its data paths, then a
bit-serial ALU in the TMS9900 would cause it to become a 1-bit machine.

I believe that there were other bit-serial ALU micros in the early
days--maybe the SC/MP?  Memory fails me at this point.

--Chuck